grammar/typo fixes in README.md & contributing.md

[Emmanuel-Melon]

Hey there! I came across a few issues in the README.md and CONTRIBUTING.md sections. Issues List

• Grammatical errors and typos in the contributing.md and README.md files.
• Add missing contributor information (full name and profile links) in the (Contributors)[https://github.com/devckla/devckla.github.io#todo] section.
• Removing nested and unstructured items in the (Todo)[https://github.com/devckla/devckla.github.io#todo] section and adding checkboxes instead.
• Improve content formatting by adding Markdown links.